(1) Field of the Invention
The present invention relates generally to agricultural implements such as disks, and, more specifically, to leveling systems providing on-the-go adjustments.
(2) Related Art
U.S. Pat. No. 4,809,786, of common ownership with the present application, shows and describes a mechanism for providing on-the-go disk harrow leveling adjustment from the cab of the towing vehicle. Rotatable screw structure having an effective length which determines the relative height and vertical force of the front and rear disk gangs includes a hydraulic motor remotely operable from the tractor cab to provide the desired disk leveling for given operating and field conditions. Although a mark or other flag device has been utilized to detect screw shaft rotation from the cab, the operator often cannot determine the position of the screw structure within its adjustment range and as a result can actually stall the motor at the range limits before he realizes that the limits are near. This inability to determine position from the cab results in additional wear and loading on the screw structure.
Providing an accurate and consistent indication on a disk leveling system involves overcoming the problem of movement of the entire leveling system relative to the machine frame during operation. A typical leveling system includes a coil spring, the compression of which not only varies with leveling adjustments but also with changing field and operating conditions.